Hydrochloric Acid
Handbook
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chemicals, vinyls, and performance chemicals directly and through various affiliates (collectively,
OxyChem). OxyChem is also North America's largest producer of sodium chlorite.
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be, recognized as some of the industry's best.
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and sound, ethical business practices.
Table of Contents
Page
INTRODUCTION TO HYDROCHLORIC ACID .................................................................................... 4
MANUFACTURING ........................................................................................................................... 4
HYDROCHLORIC ACID — USES........................................................................................................ 5
SPECIFICATIONS AND PRODUCT GRADES ......................................................................................... 6
SAFETY AND FIRST AID .......................................................................................................................... 7
HAZARDS ....................................................................................................................................... 7
RESPIRATORY PROTECTION ............................................................................................................ 8
SAFETY PRECAUTIONS ................................................................................................................... 9
FIRST AID....................................................................................................................................... 9
REGULATORY .......................................................................................................................................... 10
SPILL REPORTING......................................................................................................................... 10
HAZARDOUS CHEMICAL STORAGE REPORTING .............................................................................. 10
SECTION 313 TOXIC CHEMICAL RELEASE INVENTORY REPORTING .................................................. 11
METHODS OF HANDLING AND STORAGE ....................................................................................... 12
STORAGE ..................................................................................................................................... 12
STORAGE TANK VENTING AND HYDROCHLORIC ACID FUME SCRUBBING .......................................... 13
Storage Tank Venting ............................................................................................................. 13
Hydrochloric Acid Fume Scrubbers ........................................................................................ 14
EQUIPMENT .................................................................................................................................. 15
EQUIPMENT SOURCES .................................................................................................................. 16
UNLOADING HYDROCHLORIC ACID FROM TRANSPORTATION VEHICLES ............................................ 19
Unloading Hydrochloric Acid Tank Cars ................................................................................. 20
Unloading Procedures for Tank Cars ..................................................................................... 25
UNLOADING BY PUMP ................................................................................................................... 26
Unloading Hydrochloric Acid Tank Trailers ............................................................................ 27
Unloading Procedures for Tank Trailers ................................................................................. 29
SPILLS AND NEUTRALIZATION ........................................................................................................ 32
TECHNICAL DATA .................................................................................................................................. 33
BILLING PROCEDURE .................................................................................................................... 33
DILUTION OF HYDROCHLORIC ACID................................................................................................ 34
METHODS OF ANALYSIS ....................................................................................................................... 44
SAMPLING .................................................................................................................................... 44
DETERMINATION OF TOTAL ACIDITY ............................................................................................... 44
DETERMINATION OF GRAVITY ........................................................................................................ 45
DETERMINATION OF IRON .............................................................................................................. 46
DETERMINATION OF COLOR .......................................................................................................... 47
FURTHER INFORMATION..................................................................................................................... 48
REFERENCES ............................................................................................................................................ 48
3
Introduction to Hydrochloric Acid
Manufacturing
Hydrochloric acid, also known as muriatic acid, is an
aqueous solution of hydrogen chloride gas. Hydrochloric
acid is produced in the United States primarily by four
basic methods: the chlorination of organic chemicals, the
combination of hydrogen and chlorine, the salt-sulfuric
acid production process, and as a co-product in the
manufacture of silica. Most hydrochloric acid is produced
from the chlorination of organic chemicals with much
smaller amounts from the other processes.
OxyChem produces its hydrochloric acid by combining
hydrogen and chlorine in "acid burners." The resulting
hydrogen chloride gas is then absorbed in demineralized water to yield a high purity hydrochloric
acid.
OxyChem also markets hydrochloric acid
produced by a number of other manufacturers. This
material is a co-product from the production of other
chemicals.
OxyChem Production of Hydrochloric Acid
Drying
Liquifaction
Heater
Chlorine
Chlorine Outlet
Demineralized Water
Brine Feed
Purifier
Hydrogen
HCl Gas
HCl
Absorber
22° Bé Acid
Sodium
Carbonate
Brine
Sodium
Hydroxide
Acid
Burner
Caustic (Cell
Liquor) Outlet
Electrolytic Cell
4
Storage
Tank
Hydrochloric Acid Uses
Hydrochloric acid is an important and widely used
chemical. The largest end uses for hydrochloric acid are
steel pickling, oil well acidizing, food manufacturing,
producing calcium chloride, and ore processing.
Hydrochloric Acid End Uses
Calcium
Chloride
10%
Other
15%
Oil 18%
Steel pickling
Brine
13%
Hydrochloric acid is used in pickling operations for
carbon, alloy, and stainless steels. Steel pickling is the
process by which iron oxides and scale are removed
from the surface of steel by converting the oxides to
soluble compounds. Pickling is required for steel
products that undergo further processing such as wire
production, coating of sheet and strip, and tin mill
products. Hydrochloric acid is used primarily for
continuous pickling operations in which hot-rolled strip
steel is passed through a countercurrent flow of acid
solution.
Steel
18%
Food
26%
Hydrochloric acid is also consumed in the production of
artificial sweeteners and in the production of lysine,
choline chloride (both used primarily as animal feed
additives) and citric acid.
Production of Calcium Chloride
In addition to steel pickling, hydrochloric acid is used in
aluminum etching, metal prefixing for galvanizing and
soldering, and metal cleaning.
Neutralizing hydrochloric acid with limestone (CaCO 3)
produces calcium chloride. The largest use for calcium
chloride is highway deicing with production dependent
on weather conditions. Other uses include dust control,
industrial processing, oil recovery, concrete treatment,
and tire ballasting. Calcium chloride is also used in oil
recovery products such as drilling muds and work
over/completion fluids.
Oil well acidizing
Hydrochloric acid is used both to remove rust, scale, and
undesirable carbonate deposits in oil wells to encourage
the flow of crude oil or gas to the well. This use is called
"stimulation." Acidizing is generally done in carbonate
or limestone formations by stimulation. An acid solution
is injected into the formation, which dissolves a portion
of the rock and creates a large pore structure in the
formation, increasing its effective permeability and the
flow of oil.
Ore Processing
Hydrochloric acid is consumed in many mining
operations for ore treatment, extraction, separation,
purification, and water treatment. Significant quantities
are used in the recovery of molybdenum and gold.
Hydrochloric acid is used to convert high-grade
scheelite concentrate (CaWO4) and crude sodium
tungstate to tungstic acid, which in turn, can be used to
produce tungsten metal and chemicals. Hydrochloric
acid is also used in uranium and zirconium processing,
solution mining of borate ores, as a pH regulator in the
froth flotation of potash ores, and in rare earth extraction
from bastnasite.
Food
The food industry uses hydrochloric acid in the
processing of a variety of products. A major use of
hydrochloric acid by the food industry is for the
production of corn syrups such as high-fructose corn
syrup (HFCS). Much of the hydrochloric acid consumed
in the HFCS industry is used to regenerate the ion
exchange resins that are employed to remove
impurities. Hydrochloric acid can also be used to acidmodify cornstarch and to adjust the pH of intermediates,
final product, and wastewater. The largest use of HFCS
is in the production of soft drinks, which accounts for 7075% of demand.
Other
Aqueous hydrochloric acid is used in a variety of
miscellaneous applications. These include recovery of
semiprecious metals from used catalysts, use as a
catalyst in synthesis, use in catalyst regeneration, pH
control, regeneration of ion exchange resins used in
wastewater treatment and electric utilities, neutralization
of alkaline products or waste materials, and in brine
acidification for use in the production of chlorine and
caustic soda.
Other food uses
Hydrochloric acid is also used in other food processing
applications including the production of hydrolyzed
vegetable protein and soy sauce.
It is used in
acidulating crushed bones for the manufacture of gelatin
and as an acidifier for products such as sauces,
vegetable juices and canned goods.
Hydrochloric acid is also used in many other production
processes for organic chemicals. It can be used in the
production of p-phenylenediamine, polycarbonate
5
resins, bisphenol A, polyvinyl chloride resins, and
ethanol (from ethylene).
Specifications and Product Grades
OxyChem produces and markets Technical Grade
Hydrochloric Acid in two concentrations: 22º Baumé
(35.21% HCl by wt.) and 20º Baumé (31.45% HCl by
wt.). Other dilute concentrations of hydrochloric acid
may be available upon request
The pharmaceutical industry consumes hydrochloric
acid as a catalyst in synthesis, for pH control, for
deionization of water and as a reduction agent (e.g., in
the production of ascorbic acid and para-aminobenzoic
acid).
The Technical Grade acid meets the testing
requirements of Food Chemicals Codex as well as
ASTM Standard E 1146. Material produced and
shipped from OxyChem’s Wichita plant is Star-K Kosher
certified and is certified by NSF under ANSI/NSF
Standard 60 Drinking Water Treatment Chemicals. The
manufacturing
process
for
Technical
Grade
Hydrochloric Acid does not incorporate all of the
measures specified in the Food and Drug
Administration’s current Good Manufacturing Practices
(cGMP). It is the responsibility of the user to assess
their use of Technical Grade Hydrochloric Acid products
in food, feed, or pharmaceutical related applications and
to
determine
whether
appropriate
regulatory
requirements are being met.
Numerous other uses of hydrochloric acid include: the
manufacture of dyes and pigments; the removal of
sludge and scale from industrial equipment, the
deliming, tanning and dyeing of hides by the leather
industry, manufacture of permanent wave lotion, the
carbonizing of wool, as a bleaching and dyeing assistant
in the textile industry, and the purification of sand and
clay.
OxyChem's Technical Services Department can provide
product information for each grade of hydrochloric acid.
Call or write:
Technical Services Department
OxyChem
6200 S. Ridge Rd Wichita, KS 67215
Phone: 800-733-1165, option #1
Oxychem_tech_service@oxy.com Safety and First Aid
6
Safety & First Aid
Hazards
Hydrochloric Acid is a highly corrosive and hazardous
chemical and should be handled with extreme care.
Personnel should be properly trained in the handling of
hydrochloric acid and should always wear the proper
protective equipment when working around hydrochloric
acid. All users should read the Safety Data Sheet (SDS)
before handling hydrochloric acid.
Protective Clothing
Face Shield
Goggles
Hydrochloric acid is very corrosive to the skin and
mucous membranes and can cause severe burns to any
part of the body. The corneas of the eyes are especially
sensitive to hydrochloric acid and exposure to it or its
vapors immediately causes severe irritation. If the eyes
are not quickly and thoroughly irrigated with water,
partial or total visual impairment or blindness can occur.
Escape Respirator
It is recommended that employees be provided with and
required to use acid impervious clothing, gloves, boots,
splash proof goggles and other appropriate protective
clothing necessary to prevent any possibility of skin
contact with hydrogen chloride mists or solutions.
Material types which may be considered for this service
include nitrile, neoprene, polyvinyl chloride (PVC), butyl
rubber, Responder®, Trellchem®, and Tychem®. Face
shields should also be provided when there is a chance
of splashing liquid hydrochloric acid. Face shields can
augment protection provided by splash-proof goggles
and safety glasses, but are not intended to replace these
safety appliances.
Sleeves Over
Gloves
Hydrochloric acid has excellent warning properties.
Concentrations of 0.3 parts per million (ppm) can be
detected by smell, and concentrations above five parts
per million will cause discomfort.
Gloves
OSHA has established a ceiling value of five parts per
million (5 ppm) for hydrochloric acid. This means that
an employee's exposure to hydrogen chloride should at
no time exceed five parts per million. Effective in 2003,
the ACGIH TLV® for hydrogen chloride is a ceiling value
of 2 ppm
Trousers
Over Boots
Rubber Boots
7
have a limited service life. Conditions such as humidity,
chemical concentrations in the workplace, other
chemicals in the workplace, and frequency of use will
affect cartridge and canister service life. Therefore, an
evaluation of workplace conditions should be made to
determine
the
appropriate
cartridge/canister
replacement schedule.
Respiratory Protection
OSHA requires that employees using respirators should
be properly fitted and trained in their use.
There are three main types of respirators:
1. Escape
FULL FACE AIR PURIFYING RESPIRATOR
In areas where the unexpected release of hydrogen
chloride vapors may lead to potentially dangerous
exposure, appropriate escape respirators should be
carried by or be readily accessible to each employee.
The most common respirator used for this purpose is
the mouthpiece respirator. This respirator contains a
single cartridge with a mouthpiece and nose clip.
Employees should only use this respirator when
escape times are short and airborne concentrations of
hydrogen chloride vapors are low.
MOUTHPIECE RESPIRATOR (Escape Only)
3. Self-contained Breathing Apparatus
Self-contained breathing apparatus (SCBA) can provide
respiratory
protection
in
an
oxygen-deficient
environment and in situations where unknown
concentrations of hydrogen chloride vapors are present.
The SCBA can also provide protection in emergency
situations.
SELF-CONTAINED BREATHING APPARATUS
2. Air Purifying Respirators
Air purifying respirators contain cartridges or canisters
of absorbent or reactive material to remove harmful
gases from breathing air.
These respirators are
available as either half face or full-face units. For
hydrochloric acid service, use a cartridge or canister
designed for hydrogen chloride service.
Where vapor concentration exceeds or is likely to
exceed 5 ppm, a cartridge or canister respirator should
be used. When working in environments where airborne
concentrations are irritating to the eyes, full- face piece
respirators should be used. Cartridge or canister
respirators are strictly air-purifying devices and must
never be used in an oxygen deficient atmosphere
(less than 19.5% oxygen by volume), in environments
immediately dangerous to life or health (IDLH), or
areas containing unknown concentrations of
hydrochloric acid.
It is important to remember that cartridges and canisters
8
The SCBA is an atmosphere-supplying respirator for
which the breathing air source is designed to be carried
by the user (OSHA definition). A full-face mask is
always used with this type of apparatus. OSHA requires
that when wearing the SCBA in an IDLH atmosphere
(i.e. oxygen deficient or unknown concentrations of
hydrogen chloride, as could be expected in an
emergency situation), the SCBA be operated in the
pressure demand mode and be certified by NIOSH for a
minimum service life of 30 minutes. Escape SCBA
devices are commonly used with full face pieces or
hoods and, depending on the supply of air, are usually
rated as 3 to 60 minute units.
recommendations on spills and neutralization.
First Aid
Eye Contact - The eyes should be immediately flushed
with large amounts of water continuously for at least 15
minutes. Get immediate medical attention. It is
necessary to hold the eyelids apart while flushing to
ensure complete irrigation of the eye. Washing eyes
within several seconds is essential to achieve maximum
effectiveness. A delay of a few moments or incomplete
washing can result in partial or permanent blindness.
Never attempt to neutralize hydrochloric acid in the eyes
with chemicals. Do not apply oils or ointments unless
specifically prescribed by a physician.
OSHA requires that all respirators must be NIOSH
approved and shall use breathing gas containers
marked in accordance with the NIOSH respirator
certification standard, 42 CFR part 84. For further
information on regulations pertaining to respirator
equipment, see 29 CFR 1910.134 and 30 CFR §
57.5005 For additional information see DHHS (NIOSH)
Publication No. 2005-100, NIOSH Respirator Selection
Logic 2004 or Publication No. 87-116, NIOSH Guide to
Industrial Respiratory Protection.
Skin Contact - Flush the area of contact with large
amounts of water. Contaminated clothing should be
removed while underneath a safety shower. Get
immediate medical attention.
Do not attempt to
neutralize the acid with alkaline solutions. No oils or
ointments should be applied unless specified by a
physician.
Inhalation – Remove individual to fresh air and get
immediate medical attention. In cases of severe
exposure, humidified oxygen should be administered by
someone medically trained to administer oxygen. If
respiration or pulse has stopped, have a trained person
administer Basic Life Support (Cardio-Pulmonary
Resuscitation and/or Automatic External Defibrillator)
and
CALL
FOR
EMERGENCY
SERVICES
IMMEDIATELY.
Safety Precautions
Water should always be easily accessible whenever
hydrochloric acid is stored or used. Safety showers and
eye wash fountains should be located in the immediate
work area and clearly marked. These units should be
tested on a regular basis. Portable or temporary
systems are available. Every precaution should be
taken to ensure that a suitable system is in place and
operational before handling hydrochloric acid. Only
trained and properly protected personnel should be
allowed to enter areas where hydrochloric acid is
present. ANSI Standard 2358.1 contains placement
and performance criteria for emergency eyewash and
shower equipment.
Ingestion - Get immediate medical attention.
If
individual is a fully conscious, give large amount of
water. Do not use sodium bicarbonate in an attempt to
neutralize the acid. Do not induce vomiting. Never give
anything by mouth to an unconscious person.
Traumatic Shock - Whenever injured persons are
being cared for, the person administering first aid should
watch for signs of traumatic shock. Traumatic shock
may follow serious injury and is a depressed condition
of many body functions due to inadequate blood
circulation throughout most of the body. Signs of shock
are pale, moist, cool skin, shallow and irregular
breathing, and weak pulse.
Before entering tanks or opening pipelines that have
contained hydrochloric acid, they should be drained or
pumped out and thoroughly flushed with water. Contact
with the liquid draining from the equipment should be
avoided. Do not enter a confined space (which includes
tanks or pits) without following proper entry procedures
such as 29 CFR 1910.146.
Good housekeeping practices are important where
hydrochloric acid is used. All spills should be contained
and immediately recovered or flushed with water into a
chemical sewer or a segregated holding basin which is
provided for the specific purpose of neutralization.
Hydrochloric acid must never be flushed to a sanitary
sewer or other outlet which connects to waterways or
uncontrolled runoff streams. Contact local and federal
authorities for applicable regulations.
See
Page
29
of
this
handbook
for
Beads of perspiration may be noted about the lips,
forehead, palms, and armpits. The patient may become
nauseated.
To treat shock, keep the patient lying down and as warm
and comfortable as possible. Raise the patient's feet
eight to twelve inches unless there is head injury,
breathing difficulty, or if the patient complains of added
pain.
specific
9
Regulatory
•
The regulations discussed below are specifically
applicable to hydrochloric acid. These summaries are
not intended to be complete or legal interpretations, nor
a thorough summary of all applicable regulations.
Rather, these summaries are intended to address
regulatory issues that frequently prompt questions from
users.
•
•
•
•
•
•
These summaries also do not address any similar state
or local regulations, some of which may impose
additional or different obligations from those imposed by
federal regulations. All users are responsible for a
complete review of the applicable regulations pertaining
to their own operation.
•
Reporting requirements under the Emergency
Planning and Community Right-To-Know Act
(EPCRA)
Hydrochloric acid is subject to some, but not all of the
reporting provisions of EPCRA. Since hydrochloric acid is
listed in 40 CFR Part 302.4 as a hazardous substance, it
is subject to the emergency release notification
requirements under Section 304 of EPCRA. It is also
subject to the hazardous chemical storage reporting
requirements under Section 312.
•
•
Chemical name or identity of the substance involved
in the release
If the release incident is stopped or ongoing
An indication whether the substance is an extremely
hazardous substance
An estimate of the quantity of the release into the
environment
The time and duration of the release
Whether the release was into air, water and/or land
Any known or anticipated acute or chronic health risks
associated with the emergency and, where
appropriate, advice on medical attention necessary
for exposed individuals
Proper precautions to take as a result of the release,
including evacuation (unless such information is
readily available to the community emergency
coordinator pursuant to the emergency plan)
The names and phone numbers of the persons to be
contacted for further information
Follow-up written reports must be submitted to the
LEPC and SERC "as soon as practicable" following
the release.
Hazardous Chemical Storage Reporting
As required by the rules at 40 CFR Part 370, owners/
operators of facilities storing 10,000 pounds or more per
reporting year of hydrochloric acid must report this
information to local and state authorities. An initial, onetime notification must be submitted to the LEPC, SERC,
and the local fire department within three months after
the facility begins to handle hydrochloric acid in excess
of the threshold quantity (10,000 pounds).
Hydrochloric acid (solution) is not listed under 40 CFR
Part 355 as an extremely hazardous substance.
Hydrochloric acid (in aerosol form) is listed under 40 CFR
Part 372.65 as a reportable substance, and is subject to
Toxic Chemical Release Inventory (TRI) Reporting rules
found at 40 CFR 370 and 372.
Calculations
Reportable quantity and threshold quantity limits are
based on the pounds of HCl in the solution, not the pounds
of product. As an example, the reportable quantity for 22°
Bé (35.21%) Hydrochloric acid is 14,200 lbs., or about
1,448 gallons.
Following this initial notification, these facilities must also
annually submit an Emergency and Hazardous Chemical
Inventory Form to the same authorities. Depending on
state requirements, facilities will need to use either a Tier
I or Tier II Form. The appropriate Tier I/II forms should be
obtained from the State Emergency Response
Commission.
Spill Reporting
The forms must be submitted to the LEPC, SERC, and the
local fire department by March 1st of each year. Tier I
reports must contain the following information:
The reportable quantity (RQ) for Hydrochloric Acid is
5,000 pounds (calculated as anhydrous HCl). Any spill or
release in excess of the RQ within a 24-hour period must
be reported immediately to the following agencies:
•
Local Emergency Planning Commission (LEPC)
State Emergency Response Commission (SERC)
National Response Center (800-424-8802)
•
•
And any other state or local authority requiring incident
notification. Note that some state or local authorities may
have a more restrictive reportable quantity.
An estimate (in ranges) of the maximum amount of
hydrochloric acid present at any given time during the
reporting year
An estimate of the average daily amount of the
material present during the reporting year
The general location(s) of the material at the facility.
Tier II reports contain the same information as Tier I
reports but also include the following additional
information:
At a minimum, the following information should be
reported:
•
10
A brief description of the manner of storage of the
•
material
An indication of whether the owner elects to withhold
location information of a specific hazardous chemical
from disclosure to the public under Section 324 of
EPCRA. For purposes of Tier I and Tier II reporting,
hydrochloric acid is classified as an immediate (acute)
health hazard.
EPA Risk Management Program
Facilities that use concentrated HCl (37% HCl, 22.93 B
or greater) may also be subject to the requirements of
the EPA's Risk Management Program (RMP). These
requirements apply only to facilities that manufacture,
store, use, or otherwise handle 15,000 lbs. of HCl
(40,540 lbs. of a 37% HCl solution) at any single time.
Facilities handling HCl at concentrations below 37% are
not subject to this rule.
For more information on EPCRA, see the EPA Fact
Sheet, The Emergency Planning and Community Rightto-Know Act (EPA 550-F-00-004) or call the EPA EPCRA
Hotline at 800-424-9346.
Section 313 Toxic
Inventory Reporting
Chemical
Hazardous Air Pollutants
Hydrochloric acid is listed in Section 112(b) of the Clean
Air Act Amendments of 1990 as a Hazardous Air
Pollutant (HAP). Under the Clean Air Act, the EPA is
required to develop regulations that apply to major
sources of emissions of hazardous air pollutants. A
major source is defined as any facility that has the
potential to emit 10 tons per year or more of any
hazardous air pollutant or 25 tons per year or more of
any combination of HAPs.
Release
Hydrochloric acid (in aerosol form) is listed under 40
CFR Part 372.65 as a reportable substance, and is
subject to Toxic Chemical Release Inventory (TRI)
Reporting rules. In 1996, the EPA modified the listing
for hydrochloric acid to include only “acid aerosols
including mists, vapors, gas, fog and other airborne
forms of any particle size” (61 FR 38600, 7/25/96). Nonaerosol forms of hydrochloric acid are no longer subject
to TRI reporting requirements.
National Emission Standards for Hazardous Air
Pollutants (NESHAPs) have been established for
several source categories using hydrochloric acid.
These technology-based standards require the affected
users to employ certain control technologies to reduce
emissions. Typically, record keeping, reporting, and
emission control technologies must be enhanced to
meet the requirements of these standards.
The EPA provides a guidance document to assist
facilities in determining the sources and amounts of
hydrochloric acid aerosols that are to be included in
threshold and release determinations under EPCRA
section 313. For further information, see the EPA
guidance document, EMERGENCY PLANNING AND
COMMUNITY RIGHT-TO-KNOW ACT - SECTION 313
- Guidance for Reporting Hydrochloric Acid (acid
aerosols including mists, vapors, gas, fog, and other
airborne forms of any particle size) (EPA-745-B-99-014)
NESHAPs potentially affecting hydrochloric acid users
include those for:
Pulp and Paper (40 CFR Part 63, Subpart S)
Steel Pickling – HCl Process Facilities
(40 CFR Part 63, Subpart CCC)
Hydrochloric Acid Production (40 CFR Part 63,
Subpart NNNNN)
Under Section 313, certain facilities are required to file
an annual report on Form R or Form A (available from
the EPA) if the facility "uses" 10,000 pounds or more per
year or if the facility "manufactures" or "processes"
25,000 pounds or more per year. Questions on TRI
reporting may be directed to the EPCRA hotline
(800/424-9346).
Many state and local agencies also have regulations
governing emissions of hydrochloric acid.
These
agencies should be contacted to determine if state and
local regulations affect your operation.
11
Methods of Handling and Storage
Storage
Rubber-Lined Steel Tanks
Hydrochloric acid is most commonly stored either in
rubber-lined
steel
storage
tanks
or
in
fiberglass-reinforced plastic storage tanks.
The
rubber-lined steel tanks are usually more expensive to
install and are generally used when larger volumes of
acid are stored and the chance of tank damage
(puncture, tear, etc.) is greater due to external physical
stress in a high density work or traffic area. A storage
tank should have a concrete containment dike coated
with an acid-resistant coating to confine any spilled
product. Storage tanks should be equipped with
instrumentation to accurately measure tank inventory
and provide notification if the storage tank is
approaching an over-filled condition.
The rubber-lined steel storage tank should be made of
welded steel in accordance with American Petroleum
Institute Standard 650.
The American Petroleum
Institute (API) standard is a recommendation for
material, design, fabrication, erection, and testing
requirements for above ground, atmospheric storage
tanks. Figure 1 shows a vertical, rubber-lined steel
storage tank. The steel tanks should be constructed of
ASTM-283 Grade C steel or an equivalent material, and
they should be lined with a strong, acid-resistant soft
rubber. The rubber lining should withstand a maximum
temperature of 160F and the thickness of the rubber
should be at least 3/l6 inch.
Tanks should be equipped with two 24-inch rubber-lined
manways, one at ground level and the other on top of
the opposite side of the tank. This provides better air
circulation for confined space entry. Filling nozzles
should be 3-inch, rubber-lined flanged nozzles. The
bottom drain or unloading nozzle should also be a 3-inch
rubber-lined flange nozzle. The tank manufacturer
should be consulted for a recommendation on proper
vent openings and pressure/vacuum relief systems.
FIGURE 1: Storage Tank and Scrubber
For closed loop
pump unloading.
To process or
storage tank
12
Fiberglass-Reinforced Plastic (FRP) Tanks
A fiberglass-reinforced plastic (FRP) tank is constructed
in layers of fiberglass and each layer is mixed with resin.
The selection of the resin is extremely important, and the
tank manufacturer should specify how each layer will be
constructed and specify the correct type of resin for the
specific application. Fiberglass tanks are not always
designed to withstand pressure or vacuum so proper
venting is critical, especially if the product is to be loaded
into the tank with air pressure. The tank manufacturer
should be consulted for a recommendation on proper
vent openings and pressure/vacuum relief systems.
Fiberglass storage tanks should also be equipped with
two 24-inch manways, 3-inch flanged nozzles and 3-inch
flanged product inlet line. The tank manufacturer should
be consulted for a recommendation on proper vent
openings and pressure/vacuum relief systems.
Storage Tank Venting and Hydrochloric
Acid Fume Scrubbing
Storage Tank Venting
To prevent possible tank failure, all hydrochloric acid
storage tanks should be vented so that the pressure or
vacuum ratings of the tank are not exceeded. Exceeding
the design limits of the storage tank could lead to
possible failure of the storage tank. A properly designed
vent system will maintain the tank at or near atmospheric
pressure and within the tank design parameters. A
pressure/vacuum relief device should be in place in
addition to the tank vent.
Significant increases in pressure occur when storage
tanks are being filled. As acid is transferred into the tank
and displaces air in the tank, the pressure tends to
increase unless the vent system has the capability to
relieve the pressure. When liquid is withdrawn from the
tank, an equal volume of outside air must enter the tank
through a vent system or a partial vacuum will be created
inside the tank. This vacuum could cause cracking or
collapse of the tank. Smaller changes in pressure occur
during static storage conditions due to changes in
ambient temperature.
A properly designed vent is especially important when
acid is unloaded into the storage tank from a tank car or
trailer utilizing air pressure because of the sudden surge
of air through the unloading hose and into the storage
tank at the end of unloading. The vent system must be
designed to handle this air surge condition.
The air flow rate approximates 1350 Standard Cubic
Feet per Minute (SCFM) at the completion of a typical
unloading operation. This calculation is based upon a 2-
13
inch unloading hose 25-feet long; maximum pressure in
the tank car or trailer of 30 PSIG; unloading into a
storage tank 8 ½ feet high; and with a vertical tank vent
line not exceeding 3-feet in length.
Vent designs must be based upon a specific system,
starting with the pressure/vacuum rating for the tank and
incorporating
maximum
anticipated
venting
requirements which are dependent upon: liquid flow
rates, maximum air flow rates for air unloading, transfer
line size, length and configuration, and tank
pressure/vacuum rating. As an example, using the
parameters of the 1350 SCFM air surge, the following
tank design pressures require certain vent line sizing:
(a)
A tank designed for +25-inches Water Column
requires a 3-inch diameter vent.
(b)
A tank designed for +10-inches Water Column
requires a 4-inch diameter vent.
(c)
A tank designed for +1-inch Water Column
requires a 5-inch diameter vent.
The use of a larger diameter unloading line, longer vent
line or vent line tied into a scrubber will require an even
larger size vent line. The scrubber back-pressure can
make a large difference in the pressure in the storage
tank during and immediately after unloading. A typical
packed column scrubber or re-circulating scrubber
exerts very little back-pressure, however venting into the
bottom of a vessel below a liquid head may exert a backpressure above the tank design in routine venting
operations.
The potential for over-pressuring FRP and other lowpressure design tanks when using air pressure
unloading is especially high. The air surge at the end of
unloading will cause a rapid pressure rise in the tank and
can exceed the tank design pressure unless the vent
system is sized properly. Catastrophic failures of FRP
tanks have occurred due to over-pressurization.
Professional engineering services should be employed
to design and size the vent system.
Facilities are encouraged to frequently inspect scrubber
systems for evidence of obstructions and proper
operation to minimize back-pressure buildups.
Refer to OxyChem’s Technical Data Sheet “Venting
Hydrochloric Acid Tanks” and Chlorine Institute
Pamphlet 163: Hydrochloric Acid Storage and Piping
Systems – Appendix H for additional information.
Hydrochloric Acid Fume Scrubbers
A fume scrubber should be utilized as part of the storage
system to eliminate the release of irritating and corrosive
vapors into the workplace and atmosphere, both during
unloading operations and during "static" storage
conditions. Many localities require the use of a fume
scrubber. Figures 1 illustrates the use of a re-circulating
fume scrubber in conjunction with a typical storage tank.
The re-circulating scrubber shown in Figure 2 shows
how a scrubber is utilized in a trans-loading system used
in some acid distribution facilities. This system transfers
hydrochloric acid from a tank car directly into a tank
trailer. The fume eductor draws the acid vapors from the
tank truck, and by recirculating water through the eductor
the vapors are absorbed. This system can also absorb
vapors from the tank car as it is depressurized. By
recirculating the water, the solution will gradually build
strength and eventually reach a concentration, which is
acceptable for product use.
The re-circulating fume scrubber is typically 50 to 60%
efficient. Some states require a certain hydrochloric
acid fume scrubber efficiency for a scrubber to be
covered under permit-by-rule, eliminating the need to
obtain an air permit. Facilities should check with their
respective states for air permitting requirements.
An alternative scrubbing system for acid vapors is the
use of a packed column scrubber. Water is fed into the
top of a packed column and the gas is fed into the
bottom. The acid vapors are removed from the air by
scrubbing them with the counter-current flow of water.
The air then vents out of the top of the scrubber and the
weak acid flows into a permitted disposal system.
Scrubber efficiencies of 99% or greater can be achieved
with a properly designed packed column scrubber.
Air permitting requirements, the method used to unload
or transfer material (pump or air pressure), and the
volume of hydrochloric acid throughput are key
considerations in the design and selection of a
hydrochloric acid fume scrubber.
Professional engineering services should be employed
to select and design a hydrochloric acid fume scrubber.
FIGURE 2: Tank Car Unloading to Tank Trailer Utilizing Scrubber
14
Equipment
Hydrochloric acid is extremely corrosive to metals
including the following: carbon steel, stainless steel,
nickel, Monel®1, bronze, brass, copper, Inconel®1, and
aluminum.
These are commonly used industrial
materials. Great care should be taken to avoid contact
of these materials with hydrochloric acid.
Piping – All piping systems should be well supported.
The coldest ambient temperature that may be
encountered should be considered in the selection of
piping. Lined steel is often used in piping system for
hydrochloric acid because it is the most structurally rigid
and is less likely to be adversely affected by physical
abuse. Lined steel systems also do not require gaskets
at flanged connections. The liner itself acts as the gasket
mating material.
Common lining materials are
polypropylene (PP), polyvinylidene fluoride (PVDF) and
polytetrafluoroethylene (PTFE). Pipes are typically
carbon steel manufactured to ASTM F-1545
specifications.
FRP (Fiberglass Reinforced Plastic) piping systems
used in hydrochloric acid service are constructed of
chemically resistant resins (polyesters and epoxy-based
vinyl esters are often used) that are structurally
reinforced with glass fibers during the molding process.
Consideration should be given to coating FRP piping
with an ultraviolet (UV) light resistant barrier. This will
extend the life of the piping.
Thermoplastic piping systems used in hydrochloric acid
service consist of materials such as polyvinyl chloride
(PVC), chlorinated polyvinyl chloride (CPVC),
polyvinylidene fluoride (PVDF) and perfluoroalkoxy
(PFA). Because of its weaker structure as compared to
lined steel and FRP, thermoplastics are typically used for
tank vents and other applications where structural
strength is not a requirement.
Dual laminate piping may find application in hydrochloric
acid service. This consists of a thermoplastic liner overwrapped with an FRP outer pipe. This type of piping
system provides excellent internal corrosion protection
along with strength and external corrosion resistance.
Hoses - Acid resistant hoses can be used to handle
hydrochloric acid for both suction and discharge
applications. Viton®2, natural rubber, neoprene, butyl
rubber and Hypalon®2 are some of the materials that
offer good chemical resistance to hydrochloric acid.
15
Pumps – Composite and lined-steel pumps in
hydrochloric acid service are mostly constructed of one
of the following:
PVDF (polyvinylidene fluoride)
ETFE (ethylene tetrafluoroethylene)
FRP (fiberglass reinforced plastic)
PFA (perfluoroalkoxy)
PP (polypropylene)
Centrifugal pumps are commonly used when pumping
hydrochloric acid. Magnetic drive centrifugal pumps
have an advantage in that no seal is required which
eliminates the possibility of leakage through a seal. A
double mechanical seal should be considered if sealed
pumps are used. The gland area of the pump should be
shielded for personnel protection. Hydrochloric acid
transfer or offloading pumps should be equipped with
instrumentation to prevent continued operation when the
pump is dead-headed or running dry. A minimum flow
recycle line will also help to prevent pump damage from
dead-heading.
Suction lift is required in order to unload tank cars and
tank trailers with top outlets. Self-priming centrifugal
pumps are often used for this application. Standard
centrifugal pumps will require priming if used in these
applications.
Diaphragm and other positive
displacement pumps do not require priming and may find
use in these applications. If a diaphragm pump is used,
however, and the diaphragm ruptures, fumes may be
worse because of compressed air used to operate the
pump.
Valves - Depending upon the type of valve employed, a
number of chemically resistant polymers may be suitable
for valve lining. Examples are: PFA (perfluoroalkoxy),
PTFE (polytetrafluoroethylene), PVDF (polyvinylidene
fluoride) and PP (polypropylene). Composite body ball
valves have bodies, balls, and handles made of a
fiberglass reinforced epoxy resin.
Gaskets - Suitable materials for gaskets are Teflon
envelope, Hycar®3 rubber, ethylene-propylene rubber,
or vinyl materials.
Pressure Gauges - Pressure gauges need to be
protected by a diaphragm from direct contact with
hydrochloric acid.
1
Trademark of International Nickel Company
Trademark of E.I. DuPont de Nemours Company
3
Trademark of B.F. Goodrich Chemical Co.
2
Equipment Sources
The equipment suppliers listed here are believed to be
reliable. This is, however, only a partial listing as space
does not permit a listing of every supplier of each type
of equipment.
Listing in this section is for information only and should
not be considered as a recommendation for one
supplier’s products over another.
Pumps
Flowserve Corporation
5215 N. O’Conner Blvd.; Suite 700
Irving, TX 75039
(972) 443-6500
www.flowserve.com
Piping
NOV Fiber Glass Systems
17115 San Pedro Ave Suite 200
San Antonio, TX 78232
(210) 434-5043
www.nov.com
P.E.P
50 Tannery Rd.
Branchburg, NJ 08876
(800) 407-3726
www.pep-plastic.com
Crane ChemPharma & Energy (Plastic Lined Steel)
One Quality Way
Marion, NC 28752
(828) 724-4000
www.cranecpe.com/resistoflex
ITT Goulds Pumps, Inc.
(FRP*, Teflon-lined, Ceramic)
240 Fall Street
Seneca Falls, NY 13148
(315) 568-2811
www.gouldspumps.com/
Rubber Hoses
Birmingham Rubber & Gasket Company Inc.
200 Industrial Drive
Birmingham, AL 35211
(205) 942-2541
www.bragusa.com
March Manufacturing, Inc.
(Polypropylene)
1819 Pickwick Avenue
Glenview, IL 60025
(847) 725-0580
www.marchpump.com
Goodyear Engineered Products
(866) 711-4673
www.goodyear.com
Ceco Environmental Solutions (Fybroc)
Fybroc Division
700 Emlen Way
Telford, PA 18969
(215) 723-8155
800-392-7621
www.cecoenviro.com
Rubber Belting & Hose Supply Inc.
1850 North Ohio
Wichita, KS 67214
(316) 269-1151
www.rbhinc.com
Valves
Flowserve Corporation
5215 N. O’Conner Blvd. Suite 700
Irving, TX 75039
(972) 443-6500
www.flowserve.com
Sundyne (Ansimag Inc.)
14845 W. 64th Ave.
Arvada, CO 80007-7523
(866) SUN-DYNE
www.sundyne.com
Pump Solutions Group (Wilden Pump)
22069 Van Buren Street
Grand Terrace, CA 92313-5607
(909) 422-1700
www.psgdover.com
16
ITT Engineered Valves
33 Centerville Road
Lancaster, PA 17603-2064
(717) 509-2200
http://www.engvalves.com
Composites USA, Inc.
One Peninsula Drive
North East, MD 21901
(410) 287-2700
http://www.compositesusa.com
Crane Xomox
4444 Cooper Road
Cincinnati, OH 45242
(513) 745-6000
www.xomox.com
Indelco Plastics Corp.
32 Flicker Street
Memphis, TN 38104-5918
(901) 452-6527
www.plastico-memphis.com
Crane Resistoflex (Teflon)
1 Quality Way
Marion, NC 28752
(828) 724-4000
www.resistoflex.com
Gaskets
Garlock Sealing Technologies
1666 Division Street
Palmyra, NY 14522
(800) 448-6688
www.garlock.com
Rubber-Lined Storage Tanks/Rubber Lining
Fabricators and Applicators
Gates Rubber Company
1144 15th Street
Denver, CO 80202
(303) 744-5070
www.gates.com
O’Brien Corporation
1900 Crystal Industrial Court
St Louis, MO 63114
(314) 423-4444
www.obcorp.com
Kennedy Tank & Manufacturing Company, Inc.
833 E. Sumner Avenue
Indianapolis, IN 46227
(317) 787-1311
www.kennedytank.com
Gauges
Siebe Controls Company
33 Commercial Street
Foxboro, MA 02035
(508) 543-8750
www.foxboro.com
Protective Coatings, Inc.
1602 Birchwood Avenue
Fort Wayne, IN 46803
(260) 424-2900
www.proco-fwi.com
Meriam Instrument Division
Scott & Fetzer Company
875 Bassett Rd.
Westlake , OH 44145(800) 817-7849
www.meriam.com
Fiberglass-Reinforced Plastic Tanks
Ershigs, Inc.
742 Marine Drive
Bellingham, WA 98225
(360) 733-2620
www.ershigs.com
Ashcroft Instrument Corp
681 Grand Boulevard
Deer Park, NY 11729
(866) 415-2002
www.ashcroft-gauges.com
Heil Process Equipment Company
34250 Mills Road
Avon, OH 44011
(440) 327-6051
www.heilprocessequipment.com
Jogler, Inc.
6646 Complex Dr.
Baton Rouge, LA 70809
(800) 223-8469
www.jogler.com
17
Scrubbers
Schutte and Koerting
2510 Metropolitan Drive
Trevose, PA 19053
(215) 639-0900
www.s-k.com
Acid Resistant Coatings for Concrete
Coatings Unlimited
1911 Gramblin St.
Enumclaw, WA 98022
(425) 251-3268
www.coatingsunltd.com
Artisan Industries, Inc. (Custom design only)
44 Camparelli Pkwy
Stoughton, MA 02072
(781) 893-6800
www.artisanind.com
C&M Restoration
3115 East 12th Street
Kansas City, MO 64127
(816) 920-5600
www.cmrestore.com
Croll-Reynolds Company, Inc.
6 Sample Drive
Parsippany , NJ 07054
(908) 232-4200
www.croll.com
Carboline Company
2150 Schuetz Road
St. Louis, MO 63146
(314) 644-1000
www.carboline.com
Heil Process Equipment Company
34250 Mills Road
Avon, OH 44011
(440) 327-6051
www.heilprocessequipment.com
Tnemec Corporation
2150 Schuetz Road
Kansas City, MO 64116
(816) 483-3400
www.tnemec.com
Indelco Plastics Corp
2115 Spicer Cove, Suite 118
Memphis, TN 381134
(800)-486-6456
www.plastico-memphis.com
18
Unloading Hydrochloric Acid from
Transportation Vehicles
There are two methods used to unload hydrochloric acid
from transportation vehicles: compressed air and pump.
A well-designed pump unloading system has the
following advantages:
•
•
•
•
Significantly less vapor is generated, resulting in
lower volume to the scrubber
De-pressuring the trailer or tank car after unloading
is eliminated
Line drainage is reduced by transferring most of the
acid in the hose to the pump
Pump unloading is generally faster
The following instructions for unloading hydrochloric acid
tank cars are based on good engineering practices along
with many years of industrial experience.
These
instructions are meant to serve as a general guideline
only and may not be appropriate for all unloading
circumstances. The operation of valves and equipment
which may be present in the customer's system is also
not included. If material is being offloaded into a bottomfill storage tank, an offloading sequence should be
followed that prevents back-flow of material from the
storage tank to the tank car due to back-pressure
exerted by hydrochloric acid in the storage tank.
Unloading Hydrochloric Acid Tank Cars
Preparations
The unloading track should be level. Once the car is
spotted, set the hand brake and block the wheels. The
unloading area should be designed so that any spillage
that might occur will be properly contained for recovery
or neutralization. The unloading area should be secured
to prevent the entry of untrained or unauthorized
persons.
Department of Transportation (DOT) regulations [49
CFR 174.67 (a)(2) – (a)(3)] include an outline of steps to
be taken and signage to be placed in order to properly
spot and secure the tank car and warn that unloading is
taking place. Unloading personnel should consult and
be familiar with the latest edition of this regulation.
Personnel unloading hydrochloric acid from tank cars
must be trained and made responsible for compliance as
outlined in 49 CFR 174.67 (a)(1). Unloading personnel
should consult and be familiar with the latest edition of
this regulation.
Receiving personnel should verify the correct product by
paperwork and arrange for a sample to be taken from the
tank car where required. The line into which material will
be offloaded should be labeled or tagged with the identity
of the material being offloaded. Access to top fittings on
the tank car should be provided by safe steps, platforms,
19
or drop-bridges. Guard rails for the protection of
personnel must meet OSHA standards. If air padding is
used for unloading, the air must be clean and properly
regulated.
Emergency shut-off equipment is
recommended on all product lines.
Precautions
DOT Regulations for unloading (49 CFR 174.67(i))
require that throughout the entire period of unloading,
and while the tank car is connected to an unloading
device, the tank car must be attended by the unloader.
If it is necessary to discontinue unloading a tank car for
any reason, all valves must be tightly closed and
unloading connections disconnected. This is intended to
assure that the flow of hydrochloric acid from the tank
car is carefully controlled and the tank car can quickly be
shut off should problems in unloading develop. Letters
of clarification from DOT indicate that “attending” the
unloading includes having an employee physically
present at the unloading site, or electronic monitoring
with remote shut-off equipment, or television camera
monitoring or by any means where the tank car is
monitored and the flow of hydrochloric acid can be
stopped if unloading difficulties develop.
DOT has issued a number of company-specific
regulatory exemptions to permit tank cars containing
hydrochloric acid to remain standing with unloading
connections attached when no product transfer is taking
place. Special provisions must be followed to meet the
terms of the DOT exemption. These provisions are
outlined in the exemptions, and include the designation
of an employee responsible for on-site monitoring of the
transfer facility. It is the responsibility of each unloading
site to ensure all applicable regulations are followed.
Protective equipment, as described in the Safety and
First Aid section of this handbook, must be worn while
transferring hydrochloric acid from a tank car to a storage
tank.
Before starting the unloading operation, it must be
verified that the storage tank is adequately vented to a
properly sized acid scrubber system and that the tank
will hold the entire contents of the tank car. The storage
tank must remain vented throughout the unloading
operation. If unloading with compressed air, the tank
vent and scrubber should be properly sized for the air
surge that occurs at the end of product transfer, which is
approximately 1350 SCFM (Standard Cubic Feet per
Minute) based on 30 psig air pressure. An additional
pressure/vacuum relief device with appropriate settings
should also be installed on the storage tank.
If a tank car sample is required, all pressure must be bled
off the tank car through a properly sized acid scrubber
system before opening the manway.
Well-marked emergency showers and eye wash
fountains must be located in the immediate work area
and easily accessible in case of accidental exposure.
These units should be tested on a regular basis as well
as prior to transferring product to ensure correct
operation.
Smoking should not be allowed in or around the
unloading area. If the tank car lining should fail, the
hydrochloric acid will react with the metal to form
flammable hydrogen gas.
Unloading should take place during daylight hours. If it
is necessary to unload after dark, adequate lighting must
be provided.
If a tank car must be moved before it is completely
unloaded or if it is necessary to discontinue unloading a
tank car for any reason, 49 CFR 174.67(j) specifies
disconnection and closure operations that must be
performed.
49 CFR 174.67(l) and (k) specify
disconnecting and closure operations that must be
performed after unloading is completed. Unloading
personnel should consult and be familiar with the latest
edition of this regulation.
FIGURE 3: Tank Car Dome Configurations 263 Series (Photos 1 – 5)
Rupture Disk
Assembly
Acid Discharge
Pipe
Air/Vapor
Return Valve
Manway
20
Acid Discharge
Pipe
Rupture Disk
Assembly
Fill Hole
Air/Vapor
Return Valve
Fill Hole
Rupture Disk
Assembly
Acid Discharge
Pipe
Air/Vapor
Return Valve
Manway
21
Acid Discharge
Pipe
Rupture Disk
Assembly
Air/Vapor
Return Valve
Fill Hole
Air/Vapor
Return Valve
Rupture Disk
Assembly
Acid Discharge
Pipe
Fill Hole
22
FIGURE 4: Tank Car Dome Configurations 286 Series (Photos 1 – 3)
23
24
Unloading Procedures for Tank Cars
Unloading with Compressed Air
All hydrochloric acid tank cars are unloaded from the top.
They are unloaded through the acid discharge pipe by
using either compressed air or a pump. Most OxyChem
tank cars are equipped with one of the five manway
configurations shown in the previous photos of Figure 3.
Before starting the unloading operation, it must be
verified that the storage tank will hold the entire contents
of the tank car.
25
The recommended compressed air supply assembly
referred to in the following procedures should consist of:
a check valve, pressure reducing valve, water separator,
shut-off valve, a pressure bleed-off valve connected to a
suitable scrubber system and a pressure relief valve set
at 30 psig. (See Figure 4).
Follow these instructions:
1. Start the scrubber system and make sure it is
operating properly.
2. Verify the manway configuration on the tank car,
(refer to manway arrangements Figure 3) and
connect the air supply assembly to the one inch
valve provided on the tank car. DO NOT
REMOVE THE RUPTURE DISC ASSEMBLY.
Use of the air valve allows the rupture disc on the
incoming tank car to be left undisturbed during
the unloading operation.
The rupture disc
protects against excessive pressure buildup and
must not be removed during the unloading
operation. An intact rupture disc must also be in
place when the empty tank car is returned.
3. Cautiously open the air valve on the tank car and
bleed pressure from the tank car to a suitable
scrubber system.
4. Carefully remove the blind flange on the acid
discharge pipe. NEVER REMOVE THE BLIND
FLANGE ON THE DISCHARGE PIPE UNTIL
THE TANK CAR HAS BEEN FULLY VENTED
AND DE-PRESSURED. If the blind flange is
removed before venting the tank car, acid could
be forced up the discharge pipe and spray the
person removing the flange.
5. Connect the acid unloading line to the tank car
and the other end to the storage tank inlet.
Rubber-lined or plastic flanges should be used for
all connections.
6. Close the vent valve to the scrubber.
7. Open product inlet valve on storage tank.
8. Open valves on the air supply assembly and the
tank car air valve; apply air pressure slowly
through the air valve until a steady stream of acid
is flowing into the tank. The air pressure in the
tank car should not be allowed to exceed 30 psig.
9. When the tank car is empty there will be a drop in
pressure and the sound of air rushing through the
discharge pipe. When this occurs, shut off the air
inlet valve.
10. When the unloading line is blown free of acid,
close the inlet valve to the storage tank.
26
11. Slowly open the pressure bleed-off valve on the
airline to vent the fumes to the scrubber and
allow the pressure in the tank car to be released.
This will enable the acid in the tank car dip leg to
drain back into the tank car.
12. When the pressure gauge on the air line reads
zero, close vent valve to the scrubber.
Cautiously disconnect the scrubber vent line and
the air assembly from the tank car. Replace the
plug in the air valve.
13. Bleed the pressure and residual acid from the
product hose by slowly opening the drain valve
between the hose connection and storage tank
inlet valve. Disconnect the unloading hose.
Contain any residual acid remaining in the hose
for proper disposal.
14. Disconnect the acid unloading line from the tank
car. Replace the blind flange on the acid
discharge pipe, and bolt securely in place.
Unloading By Pump
Before starting the unloading operation, it must be
verified that the storage tank will hold the entire contents
of the tank car. A self-priming, centrifugal pump proven
suitable for hydrochloric acid service must be provided
by the customer for this type of unloading. (See Figure
5)
Follow these instructions:
1. Start the scrubber system and make sure it is
operating properly.
2. Verify the manway configuration on the tank car,
(refer to Figure 3) and connect the vapor return
line to the one inch valve provided on the tank
car. DO NOT REMOVE THE RUPTURE DISC
ASSEMBLY. Use of the air valve allows the
rupture disc on the incoming tank car to be left
undisturbed during the unloading operation.
The rupture disc protects against excessive
pressure buildup and must not be removed
during the unloading operation.
An intact
rupture disc must also be in place when the
empty tank car is returned.
3. Open the air valve and bleed pressure from the
tank car to the storage tank, which is vented to a
suitable scrubber system. Leave this valve open
for make-up air while unloading to avoid pulling a
vacuum on the tank car. The dome lid may also
need to be opened slightly to allow for sufficient
make-up air. Acid vapors will flow from the
storage tank to the tank car during unloading.
4.
After the pressure has been bled off, remove the
blind flange on the acid discharge pipe. NEVER
REMOVE THE BLIND FLANGE ON THE
DISCHARGE PIPE UNTIL THE TANK CAR HAS
BEEN FULLY VENTED AND DE-PRESSURED.
If the blind flange is removed before venting the
tank car, acid could be forced up the discharge
pipe and spray the person removing the flange.
5. Connect one end of the acid unloading line to the
acid discharge flange on the tank car and the
other end to the pump inlet. Rubber lined or
plastic flanges should be used for all connections.
6. Open the pump product inlet valve and storage
tank inlet valve.
7. Next, start the pump and continue pumping until
the tank car is empty. High-volume pumps
equipped amp-sensing cutoff switches may shut
down prematurely due to vortex action within the
27
car near the end of unloading. If this occurs, restart pump and if possible, throttle pump to
assure complete unloading of the tank car.
8. When the tank car is empty, shut off the pump
and immediately close the valve at the pump inlet.
Close and secure the dome lid if opened.
9. Bleed the pressure and residual acid from the
product hose by slowly opening the drain valve
between the hose connection and storage tank
inlet valve. Disconnect the unloading hose.
Contain any residual acid remaining in the hose
for proper disposal.
10. Close the valves on the vapor return line from
the storage tank to the tank car and disconnect
the vapor return line from the tank car.
11. Replace the blind flange on the acid discharge
pipe, and bolt the flange securely in place. Also,
replace the plug in the air valve assembly.
Preparing Empty Tank Cars for Return
When returning empty tank
procedures must be followed:
cars,
the
following
1.
If it was not done in previous operations, start the
scrubber system and make sure it is operating
properly, and de-pressure the tank car through the
scrubber.
2.
Use water to wash off any hydrochloric acid which
may have spilled onto the tank car when
disconnecting and draining the unloading line.
This will prevent damage to the car and possible
exposure to railroad personnel who will be
handling the car. All wash down water must be
drained off to a suitable chemical sewer.
3.
DOT regulations (49 CFR 173.31(d)(1)) require
the persons offering the returned empty tank car
to ensure that the tank car is in proper condition
and safe for transportation. Specifically, all tank
car openings must be properly secured prior to
shipment.
The person offering the car for
shipment must also perform an external visual
inspection that includes:
(d)(1)(i) – the tank shell and heads, except where
insulation precludes an inspection, for abrasion,
corrosion, cracks, dents, distortions, defects in
welds, or any other condition.
(d)(1)(ii) – the piping, valves, fittings and gaskets
for corrosion, damage, or any other condition.
(d)(1)(iii) – bolts and nuts that may be missing or
elements that make the tank car unsafe for
transportation.
(d)(1)(iv) – inspection and tightening of closures
and fastenings by the use of a bar, wrench, or
suitable tool.
(d)(1)(v) – securement of protective housings.
(d)(1)(vi) – the pressure relief device including a
careful inspection of the frangible disc in nonclosing pressure relief devices. However, if the
tank car operates under the DOT-E-11761
exemption, the disc does not have to be inspected
unless modifications occur.
(d)(1)(viii) – tank-head puncture resistance
system, coupler vertical restraint system and
bottom discontinuity protection.
(d)(1)(ix) – required tank car markings for legibility.
(d)(1)(x) – periodic inspection date markings that
are within the prescribed intervals.
28
4.
Ensure that the tank car has proper placards.
They should read “Corrosive”.
5.
Return all cars as promptly as possible. All
problems should be discussed with OxyChem
Customer Service.
49 CFR 173.31(d)(2) outlines the legal ramifications for
failure to perform the requirements specified in 49 CFR
173.31(d)(1).
Personnel offering empty hydrochloric acid tank cars for
return should consult and be familiar with the latest
edition of this regulation.
Unloading Hydrochloric Acid Tank Trailers
The following instructions for unloading hydrochloric acid
tank trailers are based on good engineering practices
along with many years of industrial experience. These
instructions are meant to serve as a general guideline
only and may not be appropriate for all unloading
circumstances. The operation of valves and equipment
that may be present in the customer’s system is also not
included. If material is being offloaded into a bottom-fill
storage tank, an offloading sequence should be followed
that prevents back-flow of material from the storage tank
to the tank trailer due to back-pressure exerted by
hydrochloric acid in the storage tank.
Preparations
The unloading area should be arranged so that any
spillage that might occur will be properly contained for
recovery or neutralization. The unloading area should
be level and secured to prevent entrance by untrained
and unauthorized persons.
49 CFR 177.834(e) specifies requirements, including
setting the handbrake, for preventing motion of the tank
trailer during offloading.
49 CFR 177.834(2) – (3) specify attendance
requirements by a qualified person at all times during
unloading.
49 CFR 177.834(4) specifies what a qualified person is.
Carrier personnel should make certain shipping papers
and other required documentation is delivered to
responsible receiving personnel before unloading.
Carrier personnel should also receive, prior to unloading,
signed documentation from receiving personnel that the
receiving location is set up to deliver the material to the
proper storage tank and that the storage tank will hold
the entire contents of the tank trailer. Carrier personnel
should also obtain a signed delivery receipt before the
motor carrier leaves the area. Carrier personnel should
work with receiving personnel to hook up and begin the
unloading process after all procedures have been
reviewed.
Receiving personnel should verify the correct product by
paperwork and arrange for a tank trailer sample to be
taken where required. When a sample is taken, the
person collecting the sample must verify that the tank
trailer is not pressurized if the sample is taken from the
tank trailer dome. Pressure, if present, should be
relieved through a properly sized scrubber.
The line into which material will be offloaded should be
labeled or tagged with the identity of the material being
offloaded. Receiving personnel should point out the
proper connection and line into which the product will be
offloaded and verify that the storage tank will hold the
entire contents of the tank trailer.
Access to top fittings on the tank trailer should be
provided by safe steps, platforms, or drop-bridges.
Guard rails for the protection of personnel must meet
OSHA standards. If air padding (either carrier supplied
or supplied by the receiving location) is used for
unloading, the air must be clean and properly regulated
not to exceed the tank trailer maximum working
pressure.
Emergency shut-off equipment is
recommended on all product lines.
Precautions
Trained personnel wearing protective equipment are
required for safe unloading of hydrochloric acid tank
trailers. (Refer to Safety and First Aid section for
equipment needed). The unloading operation should be
continuously attended and if it should be necessary for
the operator to leave, the operation should be shut down.
Before starting the unloading operation, it must be
verified that the storage tank is adequately vented to a
properly sized acid scrubber system and that the tank
will hold the entire contents of the tank trailer. If
unloading with compressed air, the tank vent and
scrubber should be properly sized for the air surge that
occurs at the end of product transfer, which is
approximately 1350 SCFM (Standard Cubic Feet per
Minute). The storage tank must remain vented
throughout the unloading operation. An additional
pressure/vacuum relief device with appropriate settings
should also be installed on the storage tank.
If a tank trailer sample is required and must be taken
from the manway, all pressure must be bled off the tank
trailer before opening the manway. For tank trailers with
a sample valve, the sample can be taken without
bleeding off the pressure.
29
Well-marked emergency showers and eye wash
fountains should be located in the immediate work area
and easily accessible in case of accidental exposure.
These units should be tested on a regular basis as well
as prior to offloading to ensure correct operation.
Receiving personnel should point out to carrier
personnel the exact location of these units prior to
beginning unloading.
Smoking should not be allowed in the unloading area. If
the tank trailer lining should fail, the hydrochloric acid will
react with the metal to form flammable hydrogen gas.
Unloading should be done during daylight hours. If it is
necessary to unload after dark, adequate lighting should
be provided.
Unloading Procedures for Tank Trailers
Unloading with Compressed Air
Before starting the unloading operation, it must be
verified that the storage tank will hold the entire contents
of the tank trailer. (See Figure 6)
Follow these instructions:
1.
Start the scrubber system and make sure it is
operating properly.
2.
Connect the vapor line from the tank trailer to the
fume scrubber. Open bleed valve to de-pressure
the tank trailer. Disconnect the vapor line to the
scrubber prior to opening manway for sampling.
(These steps are not necessary if manway is not
to be opened for sampling.)
3.
Connect the unloading hose to the tank trailer’s
outlet and the storage tank’s inlet. Rubber-lined or
plastic flanges should be used for all connections.
4.
Connect the unloading air hose to the tank trailer’s
air inlet.
5.
Open the inlet valve on the storage tank.
6.
Open the tank trailer’s outlet valve.
7.
Slowly apply air pressure until there is a steady
flow of acid into the storage tank. The air pressure
in the tank trailer must not be allowed to exceed
30 psig. The person performing the unloading
should verify that the scrubber is operating
properly and that fumes are not being released to
the atmosphere. It should also be verified that the
unloading hose and other transfer system
components are not leaking hydrochloric acid or
HCl fumes.
8.
When the trailer is empty, shut off compressor or
other source of air pressure.
9.
Allow acid to be blown through the unloading line
into the storage tank. If the customer’s scrubber
system is adequately sized, depressurize the tank
trailer through their scrubber system.
10.
Close the product inlet valve to the storage tank
and the tank trailer’s outlet valve.
11.
Bleed the pressure and residual acid from the
product hose by slowly opening the drain valve
between the hose connection and storage tank
inlet valve. Disconnect the unloading hose.
Contain any residual acid remaining in the hose for
proper disposal.
12.
Disconnect the unloading hose from the
customer’s transfer system. If any acid has spilled
on the outside of the tank trailer or on the ground,
it should be washed off with plenty of water and
30
drained into an appropriate chemical sewer.
13.
Check all valves and connections to make certain
they are closed and capped.
Unloading By Pump
Before starting the unloading operation, it must be
verified that the storage tank will hold the entire contents
of the tank trailer. A self-priming, centrifugal pump
proven suitable for hydrochloric acid service must be
provided by the customer for this type of unloading. (See
Figure 7)
Follow these instructions:
1.
Start the scrubber system and make sure it is
operating properly.
2.
Connect a vent line to the air/vapor return
connection on the tank trailer and bleed pressure
from the trailer to the scrubber system.
3.
Disconnect the scrubber line and connect the
vapor return line from the storage tank to the tank
trailer. This vent must remain open to avoid pulling
a vacuum on the tank trailer during unloading.
Acid vapors will flow from the storage tank to the
tank trailer during unloading.
4.
Connect one end of the acid unloading hose to the
tank trailer’s outlet and the other end to the
customer's pump inlet. Rubber-lined or plastic
flanges should be used for all connections.
5.
Open the outlet valve on the acid discharge piping
on the tank trailer.
6.
Open the pump product inlet valve.
7.
Start the pump and continue pumping until the
tank trailer is empty. The person performing the
unloading should verify that the scrubber is
operating properly and that fumes are not being
released to the atmosphere. It should also be
verified that the unloading hose and other transfer
system components are not leaking hydrochloric
acid or HCl fumes.
31
8.
After the tank trailer has been emptied, shut off the
pump and close the pump product inlet valve and
the tank trailer product outlet value.
9.
Bleed the pressure and residual acid from the
product hose by slowly opening the drain valve
between the hose connection and storage tank
inlet valve. Disconnect the unloading hose.
Contain any residual acid remaining in the hose for
proper disposal.
10.
Disconnect the unloading hose from the
customer’s pump inlet and secure the hose on the
tank trailer.
11.
Close the air/vapor returns valve and disconnect
the vapor return line.
12.
Check all valves and connections to make certain
they are closed and capped.
Spills & Neutralization
Containment of a spill or leak is of primary importance.
The storage tank should have an impervious
containment dike and the entire hydrochloric acid
unloading area should be designed to properly contain
any spills. All persons working around the spill area
should wear the full set of protective equipment as
recommended in the Safety and First Aid Section, page
5. Rubber boots are absolutely necessary when working
around a spill. Personnel should keep upwind of the
spill, and if it is necessary to enter the spill area, a
self-contained breathing apparatus should be worn.
People who are not involved with the leak or spill should
be kept away.
Facilities expecting employees to engage in emergency
response must develop an emergency response plan as
specified by OSHA in 29 CFR 1910.120(q). Where
employees are not expected to assist in handling
emergencies, an emergency response plan is not
required; however, an emergency action plan in
accordance with 29 CFR 1910.38(a) is required.
Courtesy notifications to the National Response Center
(NRC), state, and local authorities should be made
anytime an appreciable amount of hydrochloric acid is
spilled. See spill reporting information on page 10.
The hydrochloric acid can be neutralized with an alkaline
material but the reaction between concentrated
hydrochloric acid and an alkali gives off heat and can be
quite violent. Therefore, the acid should first be diluted
by using a water spray and then neutralized. The spray
will also reduce the fuming of the hydrochloric acid.
Alkaline materials to be used and quantities necessary
for neutralization are shown in Table 1. Caution should
be taken to ensure the diluted acid remains contained.
Cleanup and waste disposal must conform to current
hazardous waste regulations.
Table 1: Quantities of Various Alkalis Required to Neutralize 100 Gallons of
Hydrochloric Acid
Hydrochloric (Muriatic) Acid
Neutralizing Chemicals
Acid
Concentration
Wt.% HCl
Specific
Gravity
Solution
Actual
Pounds of
Acid per
100 Gals.
CaO
Quicklime
Ca(OH)2
Lime
Lbs.
Lbs.
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
2.0
3.0
4.0
5.0
6.0
10.0
20.0
25.0
30.0
35.0
USE 1.000
USE 1.000
USE 1.000
USE 1.000
USE 1.0015
USE 1.0015
USE 1.0015
USE 1.0015
USE 1.0015
1.0032
1.0082
1.0131
1.0181
1.0230
1.0279
1.0474
1.0980
1.1261
1.1526
1.1778
.837
1.674
2.511
3.35
4.19
5.02
5.86
6.70
7.53
8.37
16.83
25.41
33.99
42.73
51.47
87.41
183.3
234.8
288.4
343.8
.644
1.28
1.93
2.58
3.19
3.86
4.51
5.15
5.79
6.44
12.94
19.54
26.14
32.86
39.56
67.22
141
179
221
264
.852
1.70
2.52
3.41
4.22
5.11
5.93
6.82
7.63
8.52
17.12
25.79
34.53
43.42
52.31
88.92
186
237
293
348
32
Na2CO3
Anhydrous
Soda Ash
Lbs.
1.27
2.54
3.81
5.08
6.35
7.62
8.89
10.16
11.43
12.7
24.6
37.0
49.3
62.0
74.6
126.8
267
339
419
498
50% NaOH
Liquid
Caustic Soda
Lbs.
NaOH
Flake Caustic
Soda
Lbs.
1.836
3.672
5.50
7.34
9.18
11.02
12.86
14.68
16.52
18.36
36.96
55.70
74.4
93.6
112.8
191.4
402
512
632
752
.918
1.836
2.75
3.67
4.59
5.51
6.43
7.34
8.26
9.18
18.48
27.85
37.2
46.8
56.4
95.7
201
256
316
376
Technical Data
Billing Procedure
Hydrochloric acid is sold on a net ton basis as 20º Bé or
22º Bé hydrochloric acid. It is normal practice to deliver full
tank trailer or tank car quantities.
Dilution of Hydrochloric Acid
For convenience, Table 3 was prepared for the rapid
determination of acid and water quantities used in making
some of the more standard solutions. Those values not
appearing on the chart can be calculated by using the
formulas shown below.
1. To Dilute to a Lower Strength Acid:
A = Acid solution to be adjusted
B = Desired acid solution
Lbs. of water required = (Lbs. A) (%HCl A - HCl B)
(%HCl B)
Example:
2. To Adjust to a Higher Strength Acid:
A = Acid solution to be adjusted
B = Desired acid solution
C = Stock acid of higher strength
Lbs. of stock solution = (Lbs. A) (%HCl B - %HCl A)
(%HCl C - %HCl B)
Example:
500 gallons of 7.15% HCl is to be adjusted to 12%
HCl by using 20.1 Bé acid. How much 20.1 Bé acid
should be used?
A = 7.15% HCl
B = 12% HCl
C = 31.64% HCl (from Dilution Table, Table 3)
Lbs. A = gallons of A x specific gravity (from Table 4,
Equivalent Properties) x 8.34
1000 gals. of 22º Bé acid is to be diluted to 12% HCl.
How much water is needed?
= 500 gallons x 1.0357 x 8.34
= 4319 lbs.
A = 35.21% HCl (from Dilution Table)
B = 12.0% HCl
Lbs. A = gals. of A x specific gravity (from Table 3) x 8.34
= 1000 gallons x 1.1789 x 8.34
= 9832 pounds.
Lbs. C = (4319 lbs.) (12% - 7.15%)
(31.64% - 12%)
= 1067 lbs. of 20.1 Bé acid
Gallons of C =
___________Lbs. of C______________
Specific gravity x 8.34 lbs./gallon
Lbs. of water required = (9832 lbs) (35.21%-12.0%)
12.0%
=19,016 lbs. of water required
= __1067 lbs.__
(1.1609 x 8.34)
Gallons of water = lbs. of water
8.34 lbs./gallon
= 19,016 lbs.
8.34
= 110 Gallons of 20.1 Bé Acid
= 2280 Gallons
Table 2: Miscellaneous Physical Properties
% HCl
Dilutiona
1. Heat Evolved on Infinite
@ 25°C (KCal/Mole HCl)
2. Electrical Conductivitya
(Mho/Cm x 104 )
3.
Thermal Conductivityb @ 90°F
Gm Cal/(sec) (SqCm) (°C/Cm)
4.
Surface Tension @ 68°Fb
(Dynes/Cm)
a.
b.
5%
10%
20%
30%
40%
.57
.90
1.6
2.9
4.3
3948
6302
7615
6620
5152
1.195
1.110
1.030
71.3
69.4
65.9
72.4
Kirk – Othmer, Encyclopedia of Chemical Technology
Lange’s Handbook of Chemistry
33
72.2
Table 3: Dilution Table for Muriatic Acid
Gallons of Acid and Water to Make 1000 Gallons Dilute Acid
Stock Acid
Strength
Sp.Gr.
°Bé
18.0
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
18.9
19.0
19.1
19.2
19.3
19.4
19.5
19.6
19.7
19.8
19.9
20.0 -20.1
20.2
20.3
20.4
20.5
20.6
20.7
20.8
20.9
21.0
21.1
21.2
21.3
21.4
21.5
21.6
21.7
21.8
21.9
22.0
22.1
22.2
22.3
22.4
22.5
22.6
22.7
22.8
22.9
23.0
23.1
23.2
23.3
23.4
%HCl
27.92
28.09
28.26
28.44
28.61
28.78
28.95
29.13
29.30
29.48
29.65
29.83
30.00
30.18
30.35
30.53
30.71
30.90
31.08
31.27
31.45 -31.64
31.82
32.01
32.19
32.38
32.56
32.75
32.93
33.12
33.31
33.50
33.69
33.88
34.07
34.26
34.45
34.64
34.83
35.02
35.21
35.40
35.59
35.78
35.97
36.16
36.35
36.54
36.73
36.93
37.14
37.36
37.58
37.80
38.03
60/60°F
1.1417
1.1426
1.1435
1.1444
1.1453
1.1462
1.1471
1.1480
1.1489
1.1498
1.1508
1.1517
1.1526
1.1535
1.1544
1.1554
1.1563
1.1572
1.1581
1.1590
1.1600 -- I
1.1609
1.1619
1.1628
1.1637
1.1647
1.1656
1.1666
1.1675
1.1684
1.1694
1.1703
1.1713
1.1722
1.1732
1.1741
1.1751
1.1760
1.1770
1.1779
1.1789
1.1798
1.1808
1.1817
1.1827
1.1836
1.1846
1.1856
1.1866
1.1875
1.1885
1.1895
1.1904
1.1914
1.1924
Desired Strength of Dilute Acid
5% Acid
Acid
Water
161
841
160
843
159
844
157
845
156
846
155
847
154
848
153
849
152
850
151
851
150
852
149
853
148
854
147
855
146
856
145
857
144
858
143
859
142
860
141
861
140
862 I→
139
863
139
864
138
865
137
866
136
867
135
868
134
868
133
869
132
870
132
871
131
872
130
873
129
874
128
875
127
875
127
876
126
877
125
878
124
879
123
879
123
880
122
881
121
882
120
883
120
883
119
884
118
885
118
885
117
886
116
887
115
888
115
889
114
889
113
890
7 1/2% Acid
Acid
Water
244
759
242
760
241
762
239
764
237
765
236
767
234
769
233
770
231
772
230
773
228
775
226
777
225
778
223
780
222
781
221
783
219
784
218
785
216
787
215
789
[ 213→ 790 ]
212
791
210
793
209
794
208
795
206
797
205
798
204
800
202
801
201
803
200
804
198
805
197
806
196
808
195
809
193
810
192
812
191
813
190
814
189
815
187
816
186
818
185
819
184
820
183
821
182
822
181
823
180
824
179
826
177
827
176
828
175
829
174
830
173
832
172
833
10% Acid
Acid
Water
674
327
676
325
678
323
681
320
683
318
685
316
687
314
690
312
692
310
694
308
696
306
698
304
700
302
702
300
704
298
706
296
708
294
710
292
712
290
714
288
716
286
718
284
720
282
722
280
724
278
726
277
728
275
729
273
731
271
733
270
735
268
737
266
738
264
740
263
742
261
744
259
745
258
747
256
749
255
750
253
752
251
754
250
755
248
757
247
758
245
760
244
761
242
763
241
764
239
766
238
767
236
769
235
771
233
772
232
774
15% Acid
Acid Water
506
497
502
501
499
504
495
508
492
511
489
515
486
518
482
521
479
525
476
528
473
531
469
534
466
538
463
541
460
544
457
547
454
550
451
553
448
556
445
559
442
562
439
565
436
568
433
571
430
574
428
577
425
580
422
583
419
585
417
588
414
591
411
594
409
596
406
599
403
602
401
604
398
607
396
609
393
612
391
615
388
617
386
619
384
622
381
624
379
627
377
629
374
631
372
634
370
636
368
638
365
641
363
643
360
646
358
648
356
651
20% Acid
Acid
Water
690
312
686
317
681
322
676
327
672
331
667
336
662
341
658
345
653
349
648
354
645
358
641
363
636
367
632
371
628
375
624
379
620
384
615
388
611
392
607
397
603
401
599
405
595
409
591
413
587
417
584
421
580
424
576
428
572
432
569
436
565
440
561
443
558
447
554
451
550
454
547
458
543
462
540
465
537
468
533
472
530
475
527
479
524
482
520
485
517
489
514
492
511
495
508
498
505
501
502
504
499
508
495
511
492
515
489
518
485
522
28% Acid
Acid Water
997
990
983
977
970
964
957
951
944
938
931
925
919
913
907
901
895
889
883
877
871
866
860
854
849
843
838
833
827
821
816
811
806
801
796
790
786
781
776
771
766
761
757
752
748
743
739
734
730
725
720
715
711
706
3
10
17
23
30
36
43
49
57
63
70
76
82
88
94
100
106
112
119
125
131
136
142
148
153
159
164
170
176
182
187
192
197
202
207
214
218
223
227
233
238
243
247
252
257
262
266
271
275
280
285
291
285
300
Example: To make 1,000 gallons 7 ½% dilute acid from 20 °Bé stock acid, use 213 gallons of stock acid and 790 gallons water (see
bracketed figures in 20.0 line above). Although gallons of acid plus gallons of water total more than 1000 gallons, only 1,000 gallons of
dilute acid will result when mixed.
34
Table 4: Hydrochloric Acid Equivalent Properties
°Bé
1.00
2.00
3.00
4.00
5.00
5.25
5.50
5.75
6.00
6.25
6.50
6.75
7.00
7.25
7.50
7.75
8.00
8.25
8.50
8.75
9.00
9.25
9.50
9.75
10.00
10.25
10.50
10.75
11.00
11.25
11.50
11.75
12.00
12.25
12.50
12.75
13.00
13.25
13.50
13.75
14.00
14.25
14.50
14.75
15.00
15.25
15.50
15.75
Sp. Gr.
60/60°F
1.0069
1.0140
1.0211
1.0284
1.0357
1.0375
1.0394
1.0413
1.0432
1.0450
1.0469
1.0488
1.0507
1.0526
1.0545
1.0564
1.0584
1.0603
1.0623
1.0642
1.0662
1.0681
1.0701
1.0721
1.0741
1.0761
1.0781
1.0801
1.0821
1.0841
1.0861
1.0881
1.0902
1.0922
1.0943
1.0964
1.0985
1.1006
1.1027
1.1048
1.1069
1.1090
1.1111
1.1132
1.1154
1.1176
1.1197
1.1219
% HCl
1.40
2.82
4.25
5.69
7.15
7.52
7.89
8.26
8.64
9.02
9.40
9.78
10.17
10.55
10.94
11.32
11.71
12.09
12.48
12.87
13.26
13.65
14.04
14.43
14.83
15.22
15.62
16.01
16.41
16.81
17.21
17.61
18.01
18.41
18.82
19.22
19.63
20.04
20.45
20.86
21.27
21.68
22.09
22.50
22.92
23.33
23.75
24.16
°Bé
16.0
16.1
16.2
16.3
16.4
16.5
16.6
16.7
16.8
16.9
17.0
17.1
17.2
17.3
17.4
17.5
17.6
17.7
17.8
17.9
18.0
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
18.9
19.0
19.1
19.2
19.3
19.4
19.5
19.6
19.7
19.8
19.9
20.0
20.1
20.2
20.3
20.4
20.5
20.6
20.7
Sp. Gr.
60/60°F
1.1240
1.1248
1.1256
1.1265
1.1274
1.1283
1.1292
1.1301
1.1310
1.1319
1.1328
1.1336
1.1345
1.1354
1.1363
1.1372
1.1381
1.1390
1.1399
1.1408
1.1417
1.1426
1.1435
1.1444
1.1453
1.1462
1.1471
1.1480
1.1489
1.1498
1.1508
1.1517
1.1526
1.1535
1.1544
1.1554
1.1563
1.1572
1.1581
1.1590
1.1600
1.1609
1.1619
1.1628
1.1637
1.1647
1.1656
1.1666
35
% HCl
24.57
24.73
24.90
25.06
25.23
25.39
25.56
25.72
25.89
26.05
26.22
26.39
26.56
26.73
26.90
27.07
27.24
27.41
27.58
27.75
27.92
28.09
28.26
28.44
28.61
28.78
28.95
29.13
29.30
29.48
29.65
29.83
30.00
30.18
30.35
30.53
30.71
30.90
31.08
31.27
31.45
31.64
31.82
32.01
32.19
32.38
32.56
32.75
°Bé
20.8
20.9
21.0
21.1
21.2
21.3
21.4
21.5
21.6
21.7
21.8
21.9
22.0
22.1
22.2
22.3
22.4
22.5
22.6
22.7
22.8
22.9
23.0
23.1
23.2
23.3
23.4
23.5
23.6
23.7
23.8
23.9
24.0
24.1
24.2
24.3
24.4
24.5
24.6
24.7
24.8
24.9
25.0
25.1
25.2
25.3
25.4
25.5
Sp. Gr.
60/60°F
1.1675
1.1684
1.1694
1.1703
1.1713
1.1722
1.1732
1.1741
1.1751
1.1760
1.1770
1.1779
1.1789
1.1798
1.1808
1.1817
1.1827
1.1836
1.1846
1.1856
1.1866
1.1875
1.1885
1.1895
1.1904
1.1914
1.1924
1.1934
1.1944
1.1953
1.1963
1.1973
1.1983
1.1993
1.2003
1.2013
1.2023
1.2033
1.2043
1.2053
1.2063
1.2073
1.2083
1.2093
1.2103
1.2114
1.2124
1.2134
% HCl
32.93
33.12
33.31
33.50
33.69
33.88
34.07
34.26
34.45
34.64
34.83
35.02
35.21
35.40
35.59
35.78
35.97
36.16
36.35
36.54
36.73
36.93
37.14
37.36
37.58
37.80
38.03
38.26
38.49
38.72
38.95
39.18
39.41
39.64
39.86
40.09
40.32
40.55
40.78
41.01
41.24
41.48
41.72
41.99
42.30
42.64
43.01
43.40
36
37
38
39
40
41
42
43
Methods of Analysis
2.
Sampling
It is imperative that proper sampling procedures be
followed because the presence of extremely small
quantities of metal will cause discoloration of the
hydrochloric acid. Iron is the most common contaminant
and hydrochloric acid containing iron will have a yellow
color.
1.
2.
3.
The railcar or truck should be sampled from the top
through the manway. CAUTION: Railcar may be
pressured. Manway should be opened carefully
after pressure has been bled off. A glass or plastic
sample bottle should be used, and the caps should
be plastic. The cap lining should be an acid
resistant material. The sample bottle should be
thoroughly washed and dried before using.
The sample should be taken a few inches below
the top surface of the acid. The sampling
apparatus should be constructed of acid resistant
materials. Care should be taken to assure that no
metal is accidentally dropped into railcar or truck.
A few flakes of rust or a small washer could
discolor an entire load of acid.
Sodium Hydroxide, Standard Solution, 0.5
Normal: Standardize against primary standard
potassium acid phthalate (KHC8H404, abbreviated
KHP) which has been dried in a glass container at
120ºC for 2 hours. Cool in a desiccator. Weigh
out 4.0 grams of KHP to the nearest 0.1 mg, add
50 to 100 ml de-ionized water, and stir gently to
dissolve. Add 3 drops phenolphthalein indicator.
Titrate with NaOH to a pink end point. Calculate
the normality of the NaOH solution as follows:
A=
B
__________
0.20423 x C
where:
A = normality of the NaOH solution,
B = grams of KHP used, and
C = milliliters of NaOH solution consumed.
Duplicate determinations which agree within 0.0010
normality units are acceptable for averaging, with a 95%
confidence level.
Correct each subsequent titration for differences in
temperatures according to the following formula:
N = Ns + 0.00014(s-t)
If an off-color acid sample is obtained, resample
the railcar or truck. Examine sampling equipment
for metallic surfaces which could come into contact
with the acid.
where:
N = normality of NaOH solution at temperature t,
Ns = normality of NaOH solution at temperature s,
during standardization,
s = temperature of NaOH solution during
standardization, ºC, and
t = temperature of NaOH solution during
analysis, ºC.
Determination of Total Acidity
Apparatus
1. Burette, 50 ml, Class A.
2. Iodine flasks, glass-stoppered, 125 ml.
Procedure:
3. Analytical balance.
1.
Transfer approximately 30 ml of de-ionized water
to a 125 ml glass-stoppered iodine flask, stopper,
and weigh to the nearest 0.1 mg.
2.
Add rapidly a convenient size sample, depending
upon the acid strength as given in Table 5, stopper
immediately, and reweigh.
3.
Add 3 to 5 drops of phenolphthalein indicator
solution.
4.
Record the temperature of the 0.5 N NaOH
solution, and then titrate the sample to a pink end
point.
5.
Record the titration to the nearest 0.02 ml.
4. Pipette, 3 ml.
5. Thermometer, centigrade.
Reagents:
1.
Phenolphthalein Indicator, alcoholic solution:
Dissolve 1 gram of phenolphthalein in 100 ml of
ethanol.
Satisfactory end points may be
determined by titrating to the first trace of pink that
persists for 15 seconds of swirling, when titrating
a strong acid such as HCl.
44
Table 5: Sample Size for Total Acidity
HCl, percent
37
35
33
31
29
27
Baumé
22.9°
21.6°
20.8°
19.8°
18.6°
17.5°
Calculation:
1.
Record as V the delivered volume at the recorded
temperature.
2.
Calculate the total acidity as percentage of
hydrochloric acid as follows:
%HCl = V x N x 0.03646 x 100
W
where:
V = milliliters of NaOH solution required for titration
of the sample.
N = temperature corrected normality of the NaOH
solution
W = grams of sample used.
3.
Insert the hydrometer to the level at which it floats.
As the hydrometer is released, spin it gently. This
will center the hydrometer in the cylinder, help
dislodge any air bubbles which may be clinging to
the hydrometer, and release surface tension
distortions of the meniscus.
4.
Read the hydrometer. The correct reading is that
point of the hydrometer scale at which the surface
of the liquid cuts the scale. Determine this point by
placing the eye slightly below the level of the liquid
and slowly raising the eye until the surface, first
seen as a distorted ellipse, appears to become a
straight line cutting the hydrometer scale.
5.
Insert the thermometer into the cylinder and stir
gently until the thermometer reading stabilizes.
Read the temperature of the sample.
6.
Perform the above procedure fairly rapidly, as HCl
has a high vapor pressure, and the sample will
become weaker if allowed to sit open for too long a
time.
Precision:
Duplicate determinations which agree within 0.15% are
acceptable for averaging, with a 95% confidence level.
This method should yield equivalent results to ASTM E224, “Standard Test Methods for Analysis of Hydrochloric
Acid.”
Sample Size, grams
1.0 to 2.3
2.0 to 2.4
2.2 to 2.6
2.3 to 2.8
2.5 to 3.0
2.7 to 3.2
Calculation:
Determination of Gravity
1.
Apparatus:
1.
Hydrometer, streamline or torpedo design,
precision grade, for liquids heavier than water in
ranges from 17.5 to 23º Bé, with divisions of 0.1º
Bé, and standardized at 60/60º F.
B60 = Bt + 0.033(t-60)
where:
B60 = corrected Baumé at 60F
Bt = observed Baumé
t
= temperature of sample during analysis F
2.
Thermometer, 30 to 90F with 0.5 divisions.
3.
Cylinder, glass, diameter 38 to 40 mm, height 325
to 375 mm.
Procedure:
1.
2.
Correct the reading for differences in temperature
according to the following formula:
Rinse a clean hydrometer cylinder with the sample
to be tested and add the sample.
Place the cylinder in a vertical position in a location
free of air currents.
45
2.
To convert a Baumé reading to specific gravity,
calculate as follows:
________145_________
145 - Bé gravity (60/60F)
Precision:
Duplicate determinations which agree within 0.2º Baumé
are acceptable for averaging, with a 95% confidence level.
This procedure is equivalent to ASTM E-224.
Determination of Iron
Apparatus:
Procedure:
1.
A UV/Vis spectrometer or other suitable instrument
with absorbance range from 500 to 525 nm
2.
100 ml class A stoppered graduated cylinders
3.
Analytical balance capable of weighing 0.1
milligrams
3.
A one-milliliter class A pipette
4.
A 50-milliliter graduated cylinder
7.
Absorption cells, 2-cm light path
Reagents:
1.
6 Molar ammonium acetate solution (dissolve 462.5
grams in 1 liter of distilled or de-ionized water).
2.
Sodium sulfite solution (dissolve 126 grams in 1 liter
of distilled or de-ionized water).
3.
Orthophenanthroline indicator (0.2 grams of 1,10phenanthroline [monohydrate]) is dissolved in 20
mL of reagent grade ethanol and diluted to 100 mL
with distilled or de-ionized water.
4.
Distilled or de-ionized water.
5.
A standard 1,000 ppm iron solution (either can be a
purchased solution or prepared by dissolving 1.0
gram of reagent iron wire in hydrochloric acid and
diluting to 1,000 mL with distilled or de-ionized
water).
1.
Accurately weigh 1.0 to 10.0 grams of the
hydrochloric acid sample into a stoppered
graduated cylinder.
2
Dilute to 20 milliliters with de-ionized or distilled
water.
3.
Add 20 milliliters of the sodium sulfite reagent. Mix
the cylinder well.
4.
Add one milliliter of o-phenanthroline indicator to the
cylinder and mix the contents well.
5.
Add 10 milliliters of ammonium acetate buffer to the
cylinder and mix the contents well. [Note: the
contents of the cylinder should have a faint acetate
smell]. When tested with pH indicator paper, the
sample should read neutral or slightly basic. If the
odor of sulfur dioxide is present, add additional
buffer until the sulfur dioxide odor is gone.
6.
Dilute the samples to 100 milliliters with distilled or
de-ionized water and mix well.
7.
Prepare a blank containing all the reagents used in
the sample at the same time the sample is being
prepared.
8.
Allow the blank and the sample to stand for 15
minutes for full color development.
9.
Determine the absorbance of the sample at the
same wavelength used for the calibration curve,
blanking the instrument at zero absorbance with the
blank solution.
10.
Determine from the calibration curve the milligrams
of iron.
Preparation of a Standard Curve:
A.
B.
Prior to analyzing a sample, a standard curve
containing at least five points should be established.
The curve should read milligrams of iron in the final
100 mL of solution. The absorbencies of the
standards measured at 510 nm should bracket the
absorbance of the sample.
A typical iron standard curve for 20º Baumé or 22º
Baumé hydrochloric acid would have the following
iron concentration:
Calculations:
ppm Fe = mg Fe from Std. Curve X 100 X 10000
Sample weight (grams) X 1000
Precision:
This procedure should yield equivalent results to ASTM E224 under normal conditions but may give different results
with heavily contaminated samples.
.010 milligrams
.025 milligrams
.050 milligrams
.075 milligrams
.100 milligrams
46
Determination of Color
Apparatus :
Notes
1.
1.
The Aqua Tester should be placed so that the color
fields seen through the magnifying prism do not
receive direct light from behind the observer. The
color comparison is best made in a room that is not
too brightly illuminated. The darker the interior of
the light shield, the easier the color comparison.
2.
The position of the filament varies slightly in
different lamp bulbs.
Therefore, for uniform
illumination of the color fields, it is necessary to
adjust the bulb before the apparatus is first used.
Fill the two Nessler Tubes to the mark with deionized water and insert a cap in each tube. Swing
open the back cover of the Aqua Tester, rest the
bottoms of the tubes in the circular depressions in
the base of the cover, and press the tubes into the
spring clips. Close the cover and switch on the
lamp. Release the screw near the bulb socket and
slide and turn the socket until the two fields are of
equal brightness, then tighten the screw. No further
adjustment is necessary unless the bulb is
replaced.
3.
To insert a color disc, remove the light shield from
the upper platform of the apparatus housing and
place the center of the color disc on the ring, with
the number plates facing upward. Then replace the
cover. As the disc is rotated, the number plates
representing the values of the permanent glass
color standards will be seen through the circular
opening within the light shield.
4.
This method will not produce the same results as
ASTM E-224. The results will be somewhat lower
and less accurate.
2.
3.
Two Hellige® Nessler Tubes, number 611-T, with
caps, number 611-PL.
Hellige® Color Testing Disc, number 611-10,
Range 0-50 APHA.
Hellige® Aqua Tester.
Procedure:
1.
Swing open the back cover of the Aqua Tester.
Remove the right-hand Nessler tube, rinse it with
the sample to be tested, and fill it to the mark with
the sample. Insert a cap into the tube. Rest the
bottom of the tube in the right-hand circular
depression in the base of the cover, and then press
the tube into the right-hand spring clip.
2.
Remove the left-hand Nessler tube, rinse it with deionized water, and fill to the mark with de-ionized
water. Insert a cap into the tube. Place this tube in
the left-hand circular depression and press into the
left-hand spring clip. Press caps as close as
possible to each other.
3.
Close the cover and switch on the lamp.
4.
Make the color comparison by revolving the color
disc so that one standard after another is brought
into the observation field. The observation fields for
the colorimetric comparison are seen as half-fields
in the magnifying prism. The right-hand field is
produced by the Nessler tube containing the
sample. The left-hand field is formed by one of the
glass color standards in conjunction with the
Nessler tube containing water. It is necessary to
compare liquid vs. liquid media. The color fields
should be viewed with the eye in line with the center
of the magnifying prism. The half-fields should be
free of shadow effect, which is caused by off-center
of oblique observation. For normal eyesight, the
preferred viewing distance is approximately 10
inches. Do not make the mistake of placing the eye
close to the apparatus housing. Do not prolong the
observation for more than 10 to 15 seconds.
When a color match is obtained with one of the
standards, the result is read directly from the figure
seen through the circular opening within the light
shield. If the color of the sample is intermediate
between two glass standards, choose the standard
closest to the sample color.
47
Further Information
References
More detailed information on hydrochloric acid or any of
its specific applications is available on request through the
OxyChem Technical Service Department.
Annual Book of ASTM Standards, Volume 15.05,
American Society for Testing and Materials, 2002
2004 North American Emergency Response Guidebook
Call or write:
Technical Service Department
OxyChem
6200 S. Ridge Rd.
Wichita, KS 6715
Phone: 800-733-1165 Ext 1.
Email: OxyChem_Tech_Service@oxy.com
Food Chemicals Codex, 5th Edition, National Academy of
Sciences, 1996
EPA Fact Sheet, The Emergency Planning and
Community Right-to-Know Act (EPA 550-F-00-004)
49 CFR, Code of Federal Regulation Title 49 –
Transportation, Hazardous Materials Regulations, U.S.
Government Printing Office
2007 TLVs® and BEIs®, Threshold Limit Values for
Chemical Substances and Physical Agents, ACGIH®,
2007
NIOSH Respirator Decision Logic, DHHS (NIOSH)
Publication No. 87-108, May, 1987
NIOSH Guide to Industrial Respiratory Protection, DHHS
(NIOSH) Publication No. 87-116, September, 1987
Hydrochloric Acid Storage and Piping Systems,
Pamphlet 163, The Chlorine Institute, 2001
29 CFR§1910.120(q), Code of Federal Regulations Title
29 - Department of Labor, OSHA Regulations on Hazard
Communications, U.S Government Printing Office.
48
Important: The information presented herein, while not
guaranteed, was prepared by technical personnel and is
true and accurate to the best of our knowledge. NO
WARRANTY OF MERCHANTABILITY OR OF FITNESS FOR
A PARTICULAR PURPOSE, OR WARRANTY OR
GUARANTY OF ANY OTHER KIND, EXPRESS OR IMPLIED,
IS MADE REGARDING PERFORMANCE, SAFETY,
SUITABILITY, STABILITY OR OTHERWISE. This
information is not intended to be all-inclusive as to the
manner and conditions of use, handling, storage, disposal,
and other factors that may involve other or additional legal,
environmental, safety or performance considerations, and
Occidental Chemical Corporation assumes no liability
whatsoever for the use of or reliance upon this
information. While our technical personnel will be happy to
respond to questions, safe handling and use of the product
remains the responsibility of the customer. No suggestions
for use are intended as, and nothing herein shall be
construed as, a recommendation to infringe any existing
patents or to violate any federal, state, local or foreign
laws.
Occidental Chemical Corporation
Basic Chemicals Group
14555 Dallas Parkway, Suite 400
Dallas, TX 75254
800-752-5151
OxyChem Technical Services
Technical Center
6200 S. Ridge Rd
Wichita, KS 67215
800-733-1165 ext. 1
Acid Handbook
08/2022 v3
49